You need to make it fun and engaging for them. That is what the far right is doining. You and I might find it reprehensible, but they het som much traction bu having fun and giving young men a purpose and the feeling that they are doing something to netter themselves and their commuity.

How you go about that I dont know. In my local area we are focusing on having fun partiets and going out together as a group instead of just being political nerds in our own little grottos. Som far it seems to be working.

Tl;dr: Have fun visibly and invite them to join you. It takes forever, but at least you have fun while doing it.